1. Field of the Invention
This invention generally relates to the field of audio recording. More particularly, the present invention relates to a method and system of encoding audio from an analog medium into a compressed digital format using attribute information and silence detection.
2. Description of Related Art
Notwithstanding the recent advancements in digital recording and the obsolescence of analog recording technology, there exists a large number of consumers who still possess audio information (i.e., music, speeches, narrations, plays, etc.) recorded on analog media. As such, there is a growing concern that such information will, in the near future, become impracticable if not impossible, to access. This is particularly true in the music industry, where digital recordings such as compact disks (CDs), digital versatile disks (DVDs), digital audio tapes (DATs), and minidisks (MDs) provide high signal-to-noise fidelity and, for the most part, have supplanted vinyl records and analog cassette tape recordings. As a result, the consumer electronics market share, once occupied by analog reproducing devices, such as record players or cassette decks, has been overtaken by digital playback devices, making it difficult to reproduce recordings on analog media.
Moreover, unlike digital recordings, vinyl recording media is particularly susceptible to degradation. In fact, significant information loss can occur by simply playing back the recorded information due to the wear and tear on the vinyl medium itself Converting information recorded on analog media into a digital format would ensure that the content is preserved in the event that the analog media is no longer accessible due to equipment obsolescence or media degradation.
Presently, consumers are readily able to convert a digital recording from one digital format to another to facilitate storage or transmission of the recorded information. These conversions employ encoding and/or compression techniques that operate on the digital nature of the data. One such technique is specified by the well-known MP3 standard (i.e., Motion Picture Experts Group-1 Audio Layer-3 standard), which provides a compression technique that compresses digital audio files by as much as 12:1, with little perceptible loss in quality.
FIG. 1 (Prior Art) is a high-level flow diagram depicting the known conversion of selected CD digital audio files into compressed digital files stored in a computer memory. By way of example, suppose a consumer desires to store certain tracks from a CD onto computer system memory. As indicated in block B110, the consumer would first load the CD of interest into the CD-ROM drive of the computer system. The consumer would then, in block B120, invoke a xe2x80x9cripperxe2x80x9d program, which is a well-known software application that copies digital audio sequences from CDs, to copy the selected CD tracks onto the computer system memory. Examples of such ripper programs include, WinDAC(trademark) (shareware), CD Copy(trademark) (shareware), and Adaptec(trademark) Easy CD Creator 4.
The ripper program stores the selected CD tracks as audio WAV files, the format of which complies with the well-known digital audio file standard promulgated by Microsoft(copyright).
The WAV file formats the selected CD tracks as uncompressed digital audio data. A typical 2-minute stereo CD track may store as a 20 MB WAV file.
To convert the stored WAV file into a sensibly-sized digital file, the consumer would invoke an MP3 encoder application, as indicated by block B130. Examples of such MP3 encoder applications include, for example, MP3Enc(trademark) (shareware) and BladeEnc(trademark) (shareware). Some applications even integrate ripper and MP3 encoder functionality into one application such as, for example, Audiograbber(trademark) (shareware) and MusicMatch(trademark) (shareware). The MP3 application reduces the stored WAV file into a compressed digital MP3 file. In this manner, the 20 MB WAV file noted above may be compressed into a 1.5 MB digital file, with little, if any, degradation in audio quality. The audio information may then be reproduced by playing the MP3 file on an MP3 player application, such as, for example, Winamp(trademark) (shareware) and Sonique(trademark) (shareware).
Unlike CDs, however, the information recorded on analog media is neither digitally encoded nor track oriented. As such, consumers are unable to readily convert information recorded on analog media into a digital format. Therefore, what is needed is a method and system that allows consumers to encode audio from an analog medium into a compressed, track oriented digital format using attribute information and silence detection.